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mpl2dec.c
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1 /*
2  * Copyright (c) 2012 Clément Bœsch
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 /**
22  * @file
23  * MPL2 subtitles format demuxer
24  */
25 
26 #include "avformat.h"
27 #include "internal.h"
28 #include "subtitles.h"
29 
30 typedef struct {
32 } MPL2Context;
33 
34 static int mpl2_probe(AVProbeData *p)
35 {
36  int i;
37  char c;
38  int64_t start, end;
39  const unsigned char *ptr = p->buf;
40  const unsigned char *ptr_end = ptr + p->buf_size;
41 
42  for (i = 0; i < 2; i++) {
43  if (sscanf(ptr, "[%"SCNd64"][%"SCNd64"]%c", &start, &end, &c) != 3 &&
44  sscanf(ptr, "[%"SCNd64"][]%c", &start, &c) != 2)
45  return 0;
46  ptr += strcspn(ptr, "\r\n") + 1;
47  if (ptr >= ptr_end)
48  return 0;
49  }
50  return AVPROBE_SCORE_MAX;
51 }
52 
53 static int read_ts(char **line, int64_t *pts_start, int *duration)
54 {
55  char c;
56  int len;
57  int64_t end;
58 
59  if (sscanf(*line, "[%"SCNd64"][]%c%n",
60  pts_start, &c, &len) >= 2) {
61  *duration = -1;
62  *line += len - 1;
63  return 0;
64  }
65  if (sscanf(*line, "[%"SCNd64"][%"SCNd64"]%c%n",
66  pts_start, &end, &c, &len) >= 3) {
67  *duration = end - *pts_start;
68  *line += len - 1;
69  return 0;
70  }
71  return -1;
72 }
73 
75 {
76  MPL2Context *mpl2 = s->priv_data;
77  AVStream *st = avformat_new_stream(s, NULL);
78  int res = 0;
79 
80  if (!st)
81  return AVERROR(ENOMEM);
82  avpriv_set_pts_info(st, 64, 1, 10);
85 
86  while (!url_feof(s->pb)) {
87  char line[4096];
88  char *p = line;
89  const int64_t pos = avio_tell(s->pb);
90  int len = ff_get_line(s->pb, line, sizeof(line));
91  int64_t pts_start;
92  int duration;
93 
94  if (!len)
95  break;
96 
97  line[strcspn(line, "\r\n")] = 0;
98 
99  if (!read_ts(&p, &pts_start, &duration)) {
100  AVPacket *sub;
101 
102  sub = ff_subtitles_queue_insert(&mpl2->q, p, strlen(p), 0);
103  if (!sub)
104  return AVERROR(ENOMEM);
105  sub->pos = pos;
106  sub->pts = pts_start;
107  sub->duration = duration;
108  }
109  }
110 
112  return res;
113 }
114 
116 {
117  MPL2Context *mpl2 = s->priv_data;
118  return ff_subtitles_queue_read_packet(&mpl2->q, pkt);
119 }
120 
121 static int mpl2_read_seek(AVFormatContext *s, int stream_index,
122  int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
123 {
124  MPL2Context *mpl2 = s->priv_data;
125  return ff_subtitles_queue_seek(&mpl2->q, s, stream_index,
126  min_ts, ts, max_ts, flags);
127 }
128 
130 {
131  MPL2Context *mpl2 = s->priv_data;
132  ff_subtitles_queue_clean(&mpl2->q);
133  return 0;
134 }
135 
137  .name = "mpl2",
138  .long_name = NULL_IF_CONFIG_SMALL("MPL2 subtitles"),
139  .priv_data_size = sizeof(MPL2Context),
143  .read_seek2 = mpl2_read_seek,
145  .extensions = "txt,mpl2",
146 };